Predictive models of quality of life, functional capacity and fatigue in individuals with acromegaly

Abstract

Introduction: Acromegaly is a chronic systemic disease caused by excessive production of growth hormone (GH) and insulin-like growth factor-I (IGF-I). Patients with acromegaly usually presente with clinical limitations, however there are no studies that have determined influence of these characteristics on quality of life, functional capacity and general fatigue in this population. Objective: To evaluate whether the hormonal profile, arterial function and physical capacity are predictors of quality of life, functional capacity and general fatigue in patients with acromegaly. Methods: Cross-sectional study, including 23 patients (17 with active disease and 6 with controlled disease), aged over 18 years, recruited at the Acromegaly Clinic of the University Hospital Clementino Fraga Filho (HUCFF), Federal University of Rio de Janeiro (UFRJ), Brazil. The subjects underwent a laboratory analysis; body composition analysis; evaluations of peripheral arterial function (pulse wave analysis - with pulse wave velocity (PWV), arterial compliance (AC) and reflection index (IR1,2) - and the ankle-brachial index); physical capacity (manovacuometry, dominant upper limb dynamometry (DYN) and six-minute walk test (6MWT)). Furthermore, were used quality of life (AcroQoL) and physical activity questionnaires (IPAQ) and general fatigue scales (FACIT-F and MFIS). Multivariate analysis was performed by testing different models of multiple linear regression to identify predictors for AcroQoL, 6MWT and MFIS. The coefficient of determination was used to classify the quality of the models, and the significance level was set at 5%. Results: The best prediction model for AcroQol (R2 = 0,247; adjusted R2 = 0,128; SEE = 16,783 e P = 0,137) was 38,706 + (2,541 x IGF-I) - (1,555 x AC) + (35,174 x DYN); 6MWT (R2 = 0,165; adjusted R2 = 0,0336; SEE = 0,145 e P = 0,318) was 0,844 + (0,000155 x IGF-I) - (0,0788 x IR1,2) + (0,372 x DYN); MFIS (R2 = 0,378; adjusted R2 = 0,280; SEE = 16,081 e P = 0,026) was 48,855 - (7,913 x IGF-I) + (1,483 x AC) - (23,281 x DYN). Conclusion: The general fatigue of patients with acromegaly can be predicted, with statistical significance, by hormonal, peripheral vascular integrity and physical variables.